Transfer mechanism for right-angle conveyer lines



y 13, 1954. w. G. BOEHM 2,678,715

TRANSFER MECHANISM FOR RIGHT-ANGLE CONVEYER LINES Filed Jan. 4, 1950 3 Sheets-Sheet 1 I N V EN TOR.

May 18, 1954 w. G. BOEHM 2,678,715

TRANSFER MECHANISM FOR RIGHT-ANGLE CONVEYER LINES Filed Jan. 4, 1950 3 Sheets-Sheet 2 I MUM 6 50am May 18, 1954 w. G. BOEHM 2,673,715

TRANSFER MECHANISM'FOR RlGHT-ANGLE CONVEYER LINES 3 Sheets-Sheet 3 Filed Jan. 4, 1950 INVENTOR. Mars? 6 Ba Patented May 18, 1954 TRANSFER MECHANISM FOR RIGHT-ANGLE CONVEYER LINES Walter G. Boehm, Detroit, Mich., assignor to Palmer-Bee Company,

ration of Michigan Detroit, Mich, a corpo- Application January 4, 1950, Serial No. 136,699

8- Claims.

This invention relates to a transfer mechanism for moving loads from one conveyor to another, and more particularly to a mechanism adapted to transfer rigid loads between conveyors running at right angles to each other.

In steel mill operations it is frequently necessary to transfer coiled rolls of sheet steel carried endwise on one conveyor to another conveyor running at right angles thereto. Various types of 90 transfers have been employed which might be generally classified as roller. chain, power and rotary transfers,

In the roller type transfer, a gravity roller table pivots opposite the head shaft of the first conveyor and coils of steel roll on to this gravity bed and over a second conveyor, after which the gravity bed is lowered either by eccentrics or toggle-like mechanisms. After the coil travels on to the second conveyor clearing the transfer, the roller bed is pivoted again in order to receive another coil. The coils are kept central on the second conveyor by using an adjustable spring bumper to compensate for the various diameter coils.

This type of transfer is subject to certain disadvantages. For example, the edges of the coils running on the roller bed may become damaged, especially when handling thin plate coils with telescoping edges, or loose ends may hang up on the roller bed and not running completely over the second conveyor, necessitating in most cases the service of a crane; the shock when the 0011 hits the adjustable. bumper very frequently loosens the inside wrap of the coil which causes difliculties when the coil is further processed with the use of central mandrels; and the conveyor chain of the first conveyor has a tendency to damage coil edges while passing over the end sprocket.

The chain type of transfer usually comprises a third triple strand conveyor connecting the head shaft of the first conveyor with a tail shaft. of the second conveyor and is usually driven from the tail shaft of the. second conveyor. The chain must of necessity be of the universal, type, bending in two directions in order to run over end sprockets and also negotiate 90 curve. This type of transfer permits a continuous transfer of coils without interruption. However, the chain, in order to provide universal action, requires a somewhat complicated and expensive construction and, in addition, there may be damage to the edges of the coils due to the movement between the chain tops and the edges in negotiating the 90 turn, as well as where the chains go over the end sprockets.

The power roller type of transfer involves theuse of a power roller table having tapered rolls, and has about the same disadvantages as the previously described gravity roller transfer.

The rotary type of transfer involves the use of a heavy vertical column shaft which is power driven for rotation and raises and lowers with hydraulic mechanism. It is usually equipped with four coil cages which move between the ends of the conveyor lines. This type of transfer unit is very costly and the high inertia resulting from the coil standing on overhanging arms results in severe loads when stopping the rotating transfer. Furthermore, the coils must still travel over head sprockets, with resultant frequent damage to the edges thereof.

It is an object of the present invention to provide a 90 transfer unit which will overcome these various disadvantages of prior types.

Another object is to provide a transfer wherein there is never any relative sliding movement between the edge of the coil and any part of the transfer or conveyor.

Another object is to provide a transfer which is positive in its action.

Another object is to provide a transfer adapted for mounting on a weight scale in order to permit the operator for the transfer to also operate the scale.

Another object is to make the coils available for convenient marking after they are weighed.

Another object is to provide a transfer adaptable to the use of any number of feed conveyors leading to a single 90 conveyor, which is not possible with the rotary, chain or power roll types of transfers previously described due to the necessity of each of such transfers operating between head and tail shafts of the right angle conveyors.

Another object is to provide fully automatic transfer whether using one or more feed conveyors.

Another object is to provide a transfer member which may be raised between the double strands of a chain conveyor to engage a load without any relative sliding movement during engagement.

Another object is to provide mechanism for moving an engaged load longitudinally beyond the end of a feed. conveyor.

Another object is to provide mechanism between the strands of a second double chain conveyor for engaging a load transported to a position over such second conveyor.

Another object is to provide mechanism which will accommodate the retraction of the transfer member when it is engaged by such latter mechanism.

Another object is to provide means for lowering the load on to the second conveyor after the transfer member has been retracted without any relative sliding between the load and the second conveyor.

Another object is to provide timing mechanism adaptable for use in stopping and starting the two conveyors before and after each transfer operation.

Another object is to make such timing mechanism responsive to the location of the inside diameter of the coil, thereby automatically compensating for variations in the outside diameter.

Another object is to provide a transfer which is adaptable to either the same or various levels in the two 90 conveyors.

These and other objects will be apparent from the following description of a particular embodiment of my invention and from an examination of the drawings disclosing such embodiment, wherein Fig. 1 is a side elevation of the transfer mechanism taken along a plane passing longitudinally through a discharge conveyor and perpendicular to the direction of travel of the receiving conveyor;

Fig. 2 is an enlarged end elevation taken along the line 2-2 of Fig. 1;

Fig. 3 is a sectional elevation taken along the line 33 of Fig. 2;

Fig. 4 is a sectional view taken along the line 4-4 of Fig. l; and

Fig. 5 is a schematic wirin diagram showing the use of limit switches responsive to the inside diameter of the load coils for producing stopping signals for the two conveyor lines.

Referring to Fig. 1, a discharging conveyor A moves coils of steel I toward a receiving conveyor B, and the transfer mechanism for moving coils In from the conveyor A to the conveyor B includes a main platform C, a raisable platform D, a longitudinally extendable load engaging transfer member E and a raisable load engaging member F. Conveyors A and B are each of the double-strand chain conveyor type and operate intermittently, stopping each time a load is transferred from one to the other.

The transfer operation consists essentially of raising the platform D causing the member E, which extends between the strands of the chain conveyor A, to engage and raise a load Ill above the surface of the conveyor A; moving the member E longitudinally over the conveyor B to the dotted-line position shown at H raising the member F to engage and raise the load I0 off of the surface of the member E; retracting the member E; lowering the member F, thereby delivering the load l0 on to the surface of the chain conveyor B; and lowering the platform D preparatory to the movement of a new coil into position over the transfer member E.

The platform C may be mounted on a scale in a manner facilitating the weighing of each coil of steel delivered from conveyor A to conveyor B, but is otherwise stationary with respect to the floor of the plant in which the conveyors operate. Pedestals l2 and I3 at either end of the platform C mount bell crank members 14 and which pivot respectively at centers I6 and I1 and simultaneous actuation of these bell crank members through a connecting rod I8 and hydraulic cylinder I 9 move pedestals 20 and 2l which mount platform D through a vertical distance of approximately two inches. The lower limit of travel brings the engaging surface 22 of the member E approximately one inch below the surface of the chain conveyor A while the upper limit carries such engaging surface 22 to a position approximately one inch above the surface of the conveyor A. The bell crank members 84 and I5 are adapted to move the platform D in a vertical direction at the time the surface 22 engages a load Ill, so that the engaging contact is normal and avoids any sliding movement between the member E and load Hi.

When the platform D has been raised to its uppermost position raising a load It! off of the conveyor A, hydraulic cylinder 23 is actuated to move the transfer member E longitudinally over the conveyor B to the position shown by dotted line H in Fig. 1. As shown in Fig. 3, the transfer member E is fabricated as a box-like beam having a relatively Wide upper flange 24 and narrow lower flange 25 and a pair of intermediate vertical connecting members 26. As shown in Figs. 1 and 2, the vertical members 26 extend downwardly to provide a rigid connection with a cross beam, generally indicated as G, having upper and lower flanges 21 and 28, a square axle shaft 29 and connectin web members 36. The ends of the axle shaft 29 are provided with hubs 3| for flanged wheels 32 which engage upper and lower tracks 33 and 34 suitably mounted on the movable frame D, as best shown in Fig. 4. The laterally spaced wheels 32 provide lateral stability for the transfer member E, while, as shown in Figs. 1 and 3, the forward end of the member E is supported by a roller 35 journaled on a pedestal 36 on the frame D and, upon movement across the conveyor B, engages a second supporting roller 31 journaled on a pedestal 38, likewise supported on the frame D. The resilient bumpers 39 are engaged by the wheels 32 at the end of their travel.

As best shown in Fig. 2, the frames C and D, as wel1 as the wheels of the transfer member E, extend laterally beyond the conveyor tracks 46, while the load engaging portion of the member E extends upwardly between the conveyor tracks 40.

The top surface of the conveyor A is indicated by the dotted line 4|, and the chains are driven by laterally spaced sprockets, not shown, which are in turn driven by head shaft 42. Fixed guide members 43 and 44 engage the conveyor chain, guiding the same on the return reach below the platform D.

The vertically moving load engaging member F is actuated by a pair of hydraulic cylinders 45 and is stabilized by a cylindrical column 45 which is piloted in a cylindrical bore and a guide member 41 mounted on the platform D. A pair of spaced arms 48 are provided with horizontal members 49 which are adapted to extend on either side of the transfer member E and, when raised to the uppermost position, engage a load I0 raising it off of the surface of such transfer member. The stroke of the cylinders 45 is such that when the member E is retracted and the arms 48 lowered to their lowermost position the horizontal members 49 will move below the surface of the conveyor B, thereby causing the load to be deposited on the surface of such conveyor.

Since the conveyors A and B are both stopped during the transfer operation, the relative movements of the transfer member E in engaging a load l0 and the load engaging member F in engaging such load and in depositing it on the conveyor B are all in a vertical direction. Thus it will be seen that there can be no relative sliding movement in either conveyor or transfer mechanism against the engaging surface of the load at any time during the transfer operation.

In the particular operation shown, coils of steel have uniform inside diameters corresponding to the size of the mandrel on which they are wound, but nonuniform outside diameters depending on the length of the metal wound each coil to be transferred. Accordingly, it is desirable to stop the conveyor A preparatory to transfer at a given position relative to the inside diameter of the coil so that a given movement of the transfer member E may in every case cause the coil to be moved to a central position over the conveyor B. In order to provide an electrical signal for stopping the conveyor motor in response to the position of the inside diameter of a coil it, two limit switches LS! and LS2 are mounted on the upper surface 22 of the transfer member E, each adapted to be actuated by the lower surface of a coil It passing over such limit switches.

The limit switches are spaced from each other a distance less than the minimum thickness of a coil and, as may be seen in Fig. l, coil moving over the limit switches will first actuate limit switch LSi and then LS2 and, when the inside edge of the coil passes oif of the limit switch LS1, such switch will be released. With reference to Fig. 5, by providing in series a normally closed contact in limit switch LSI, which is. opened by the actuation of such limit switch, and a normally open contact in limit switch- LS2, which is closed by the actuation of such switch. a conveyor motor stopping circuit may be established in response to the position of the inner edge of the coil when it releases the limit switch LSi. Such circuit may be employed to close a relay which will in turn open a normally closed contact in series with motors for conveyor A and conveyor B. Such relay may be tripped to start conveyors A and B by a conveyor motor starting circuit established in response to the lowering of the load engaging member F actuating a limit switch LS3, as shown in Fig. 3, the tripping circuit being initially held open by the actuation of limit switch LS2 opening a normally closed contact, and then by the raising of load engaging member F re1easing limit switch LS3, thereby opening its normally closed contact.

Only that portion of the control circuit for starting and stopping the conveyor motors has been shown and any suitable controls for operating the hydraulic cylinders is, 23 and @5 may be employed.

While hydraulic mechanism has been disclosed for actuating the transfer, equivalent mechanical means such as operated with electric motors and gearing might be substituted, and w ile a particular embodiment in other respects been described. above in detail in connection with a specific steel-mill application, it will be understood that numerous modifications in detailed construction and application might be resorted to without departing from the scope of my invenas defined in the following claims.

I claim:

1. A transfer mechanism for moving rigid loads to or from a double chain-type conveyor, characterized by a longitudinal member having a load engaging portion adapted to move transversely across the top of said chain conveyor to a load supporting position above said chains, a second load engaging member, and mechanism adapted to raise and lower said second member between extremities above and below the load support ing level of said first member, said first and sec ond load engaging members being adapted to exchange a load through changing the level of said second member, and said second load engaging member and said chain conveyor being adapted to exchange a load through changing the level of said second member.

2. A transfer mechanism for moving rigid loads to. or from a double chain-type conveyor, characterized by a transfer member having a load on gaging portion adapted to move transversely across the top of said chain conveyor to a load supporting position above said conveyor, a second load engaging member interposed between said chains, and mechanism adapted to raise and lower said second member between extremities above the load supporting level of said first memher and below the load level of said conveyor. said first and second members being adapted to exchange a load from one to the other by a change in the level of said second member.

3. A transfer mechanism for moving hollow vertical axis cylinders having uniform inside and nonuniform outside diameters from the'end of one double chain-type conveyor to a second conveyor extending past said end, characterized by a load engaging member adapted to move upwardly between said chains to engage a load at said conveyor end and to move load longitudinally a fixed distance to a central position over said second conveyor, and mechanism for establishing an electrical signal for stopping said first conveyor preparatory to transfer at a point where given load to be transferred will be said fixed distance from the center of said second conveyor, including control mechanism responsive to the location of the inner edge of said cylinder.

4.. a transfer mechanism for moving hollow vertical axis cylindrical loads having uniform inside and nonuniform outside diameters from the end of one double chain-type conveyor to a second conveyor extending past said end, characterized by a load engaging member adapted to move upwardly between said chains to engage a load at said end and to move said load longitudinally a fixed distance to a central position over said second conveyor, and mechanism for establishing an electrical signal for stopping said first conveyor preparatory to transfer at a point where a given load to be transferred will be said fixed distance from the center of said second conveyor, including a pair of limit switches positioned to be contacted by the end wall of a load approaching said conveyor end, said limit swit hes being longitudinally spaced a distance less than the minimum thickness of a cylinder wall, said switches being adapted to produce a closed circuit after the successive actuation of said first and second limit switches and the release of said first limit switch in a manner adapted to initiate the stopping point signal relative to the inside diameter of said cylindrical load.

5. A transfer mechanism for moving loads between two double chain-type conveyors, one of which extends past the end of the other, comprising a frame extending below both of said conveyors, a load engaging member on said frame located between the chains at the end of said conveyor, mechanism for raising and lowering said frame and said load engaging member to positions above and below the load level of said conveyor and to an overpassing level relative to said one conveyor, mechanism for moving said load engaging member longitudinally over said one conveyor, a second load engaging member on said frame located between the chains of said one conveyor, mechanism for raising and lowering said second load engaging member above and below the load level of said one conveyor and above and below the load level of said first load engaging member in its overpassing position.

6. A transfer mechanism for moving rigid loads between two conveyors characterized by a frame, mechanism for raising and lowering said frame, a load engaging member on said frame, mechanism for moving said load engaging member between longitudinally spaced positions, a second load en gaging member mounted on said frame in the longitudinal path of said first load engaging member, mechanism mounted on said frame for raising and lowering said second load engaging member above and below the load level of said first load engaging member, said first and second load engaging members being adapted to exchange loads therebetween when said first load engaging member is in one of its longitudinal positions through the raising and lowering of said second load engaging member.

7. A transfer mechanism for moving rigid loads between two double-chain type conveyors, one of which runs past the end of the other characterized by a frame, mechanism for raising and lowering said frame, a load engaging member located between the chains at said conveyor end and raising and lowering with said frame to positions above and below the load level of such chain in a manner whereby load may be exchanged between said conveyor end and said load engaging member, mechanism for moving said load engaging member between longitudinally spaced positions, a second load engaging member in the longitudinal path of said first load engaging member located between the chains of said one conveyor, mechanism for raising and lowering said second load engaging member above and below the load level of said first load engaging member as well as above and below the load level of said one conveyor whereby a load may be exchanged between said one conveyor and said second load engaging member.

8. A transfer mechanism for moving rigid loads between two double-chain type conveyors having different horizontal levels, one of which conveyors extends past an end of the other, a load engaging member located between the chains at said conveyor end and raising and lowering with said frame to positions above and below the load level of said latter conveyor and to an over-passing level relative to said one conveyor, mechanism for moving said load engaging member between longitudinally spaced positions, a second load engaging member in the longitudinal path of said first load engaging member located between the chains of said one conveyor, mechanism for raising and lowering said second load engaging member above and below the load level of said first load engaging member in said overpassing position as well as above and below the level of said one conveyor.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Ser. No. 368,952, Cramer (A. P. 0.), published May 18, 1943. 

